how about beans , tofu and nuts . 50-70gm of each everyday should give you plenty of nutrition combined with rice/bread/veggies . And i am sure they won't be very expensive . Which part of the world are you from mate ?

I had Red lentil puree on rice the other day ...I made a double batch because it is easy to make and fairly cheap as far as meals go. I changed the recipe a bit.. used red pepper instead of green and sauteed garlic and onions before throwing in the rest.

Rice and beans (or lentils) are about as cheap as it gets. Potatoes and sweet potatoes are good to. Throw in a few veggies and you are good.

Most people on this forum are vegan... they don't eat eggs, dairy, meat, fish, or snails so you probably don't have to worry about anyone here recommending those things to you. We may push the broccoli tho.

If it's important to you, you'll find a way. If it isn't, you'll find an excuse.